Dissociable
Aspects of Mental Workload : Examinations of the P300 ERP Component
and Performance Assessments
C. L. Baldwin & J. T. Coyne |
Advanced
technologies have enabled the choice of either visual or auditory
formats for avionics and surface transportation displays. Methods
of assessing the mental workload imposed by displays of different
formats are critical to their successful implementation. Towards
this end a series of investigations were conducted with the following
aims: 1) developing analogous auditory and visual versions of a secondary
task that could be used to compare display modalities; and 2) to
compare the sensitivity of neurophysiological, behavioral and subjective
indices of workload. Experiments 1 and 2 confirmed that analogous
auditory and visual secondary oddball discrimination tasks were of
equivalent difficulty as indicated by P300 amplitude, RT, accuracy
and subjective ratings of workload. Experiments 1-3 revealed that
RT and accuracy for target detections were generally more sensitive
to changes in primary task difficulty than P300 responses and subjective
ratings. However, Experiment 3 indicated that P300 amplitude was
sensitive to increased perceptual demands (resulting from driving
in heavy fag versus clear visibility} not revealed by changes in
either behavioral or subjective indices. Together the results of
the current investigations indicate that a battery of assessment
techniques will provide the most sensitive assessment of workload
in complex environments. Key words: mental workload assessment, display modality, transportation, neurophysiological measures, adaptive automation |